<?php

namespace PhpOffice\PhpSpreadsheet\Writer\OpenDocument;

/**
 * Copyright (c) 2006 - 2015 PhpSpreadsheet
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * @category   PhpSpreadsheet
 * @copyright  Copyright (c) 2006 - 2015 PhpSpreadsheet (https://github.com/PHPOffice/PhpSpreadsheet)
 * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
 * @version    ##VERSION##, ##DATE##
 */
class Thumbnails extends WriterPart
{
    /**
     * Write Thumbnails/thumbnail.png to PNG format
     *
     * @param   \PhpOffice\PhpSpreadsheet\Spreadsheet                   $spreadsheet
     * @throws  \PhpOffice\PhpSpreadsheet\Writer\Exception
     * @return  string                     XML Output
     */
    public function writeThumbnail(\PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet = null)
    {
        return '';
    }
}
